Inclined grate



April 12, 1949. w. s. ANDERSON, JR 2,466,789

INCLINED GRATE 2 Sheets-Sheet 1 Filed April 16, 1945 h a D f Z W C M we April 12, 1949. w. s. ANDERSON, JR

INCLINED GRA'I'E 2 Sheets-Sheet 2 Filed April 16, 1945 Patented Apr. 12 1949 INCLINED GRATE William S. Anderson, Jr., Williamsport, Pa., as-

signor to Avco Manufacturing Corporation, a

corporation of Delaware Application April 16, 1945, Serial No. 588,674

' 13 Claims. 1

The invention relates to grates. I

In magazine feed boilers or furnaces in which the solid fuel is fed onto inclined grates, the coal is usually fed onto the upper end of the grate and is progressively burned into ash as it slides downwardly on the grate. This necessitates or makes it desirable to elfect the greater shaking action in the lower portion of the grate where the greater portion of the ash is produced to cause the fuel to replace the ashes.

Heretofore, as far as I am aware, it has been the practice to provide grates having independently operable separate upper and lower gratebar sections so that the lower sections could be differentially operated to discharge the greater portion of the bed at the lower end of the grate than lesser portions from the upper sections so that the fuel will slide downwardly to displace the ashes passing into the pit. This involved the exercise of judgment and intelligence on the part of the operator in the selective operation of the upper and lower sections to maintain the fuel bed in the desired condition for progressive combustion.

One object of the invention is to provide an improved grate which comprises inclined grate bars onto which the fuel is fed from the magazine and which are inherently formed to automatically produce a greater shaking action along the lower portions of the grate than in the upper portions so that judgment need not be exercised for the relative discharge of material from the lower and upper portions of the grate.

Another object is to provide a grate of this type which includes intermediate members for graduating the discharge between the lower portion and the upper portion of the grate.

Another object of the invention is to provide an inclined rate which comprises grate bars extending continuously from the upper to lower portions of the firebox with inter-extending wings and recesses for discharging the ash from the lower portion of the grate and a formation on the upper portion of the bars for effecting lesser shaking action where the fuel has not been consumed or formed into ash.

Other objects of the invention will appear from the detailed description.

The invention consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a. section of the lower portion ofa inclined furnace magazine feed boiler provided with a grate embodying the invention.

Fig. 2 is a section taken on line 2-2 of Fig. 1.

Fig. 3 is a perspective of one of the grate bars.

Fig. 4 is a side elevation of one of the grate bars.

Fig. 5 is an end view of the lower end of one of the grate bars.

Fig. 6 is a section taken on line 6-6 of Fig. 4.

Fig. '7 is a section taken on line 1-1 of Fig. 4.

The invention is exemplified in a boiler or furnace of the sectional magazine feed type which comprises sides 12, water conduits I3 and I4 which, as well understood in the art, are communicatively connected to water legs in the sides above the water conduits; a fuel magazine l6 formed between an inner wall I! and one side of the boiler is'provided for delivering fuel by gravity onto the upper end of the grate at one side of the firebox. The grate comprises a series of grate bars generally designated 20, which are inclined downwardly from the magazine side of the boiler. Each grate bar is provided with a trunnion 22 journalled in a lug 23 at one side of the firebox and a trunnion 25 journalled in an inwardly facing recess 26 in the other boiler side. Each grate bar is provided with an integral depending ear 28 and the ears of all of the bars are connected for simultaneous rocking on their trunnions by a bar 29 which, when shifted longitudinally, will simultaneously rock all of the grate bars in the same direction.

The upper face of each rate bar is substantially flat so that the fuel will slide downwardly when the grate bars are rocked. Commencing at the trunnion 22, each grate bar comprises a central longitudinally extending rib or member 3|. Adjacent its lower end, each grate bar has an integral transversely extending wing 32 projecting from one side of the member 3!. Each wing comprises a central rib 33 which is reinforced at its under side by a rib 34 which extends from the central member 3i to the outer end of win 32 and has angular notches 35 and 36 adjacent one side of central member 3|, longitudinally extending notches 31 and 38, and an end notch 38 which extend vertically through-v wing 32. The side edges of wings 32 are convergent, from the central member 3|, as at 40 and- M, to a longitudinally extending outer end 42.. The grate bar at the side OppOSite each wing 32,-

wing 32' of a' At the side of each grate bar is :cut away as at 52 to receive the similar grate bar. opposite the side on which wing 32 .is'formed,

and longitudinally offset upwardly therefrom the bar is provided with a transversely extending wing 45, the side edges 46 of which are convergent from the central member 3! and terminate in a longitudinally extending straight end 4?. Each win 45 comprises a central rib with lugs 49 and slots 59 along its sides which extend vertically through said wing. Rib 48 extends from the outer end 41 of wing 45 to the one edge of the central member 34. The space 52 is divergent from central member 3|, and conforms to and is adapted for receiving a convergent Wing 34 on a contiguous bar. A divergent space 53 is formed between wing 32 and a second wing 55 on the same side of the bar. The lower side of wing 55 is inclined to form with the upper side of wing 32 a divergent clearance space 53 for a wing 45 on a contiguous bar, and its upper side is reversely curved as at 56. Communicating slots 58 extend through each wing 55 and lugs 59 are provided in the slots. A rib 50 extends between the outer end of wing 55 and the central member 3!. The grate bar on the opposite side of wing 55 is provided with a clearance space 62 which is contoured to receive a wing 55 on a contiguous bar, the lower edge of this space being formed by the upper convergent side 46 of wing 45 and a reversely curved side 53 of a wing 85. The outer side of wing 65 is longitudinally inclined as at 66 from the curved edge 63 to one side of a substantially rectangular or straight sided member 68 at the upper end of the grate. The sides of member 68 are equidistant from the longitudinal axis of the bar. Wing 65 is provided with a slot 69 having transversely and longitudinally connected branches with lugs H3 in the slot between which the ashes are adapted to pass through the grate bar. At the side of the grate bar opposite the wing 65 it is generally inclined as at 'H, in substantial parallelism with the edge 65 to iorm'a space for receiving and conforming to a wing 65 on a contiguous grate bar. Transverse open-ended notches 12 extend between inclined edge H and the central member 3!. The substantially rectangular member 68 extends from wing 65 and forms the upper end of the grate and is provided with transversely extending lugs M and connecting slots [5 which provide passage through the upper portion of the grate. The bottom edges 15 of lugs 14 are downwardly divergent. The sides I! of rectangular member 68 are of greater depth than the wings atthe lower end of the grate and-are arcuately contoured as at T8 to provide for rocking clearance betwen the contiguous grate bars. The lugs H' on the side opposite wings 65 are of gradually decreasing heighth from the rectangular member 68 toward the lower portion of grate bar and their ends are downwardly divergent for clearance with like lugs on contiguous bars. The front and rear walls of the boiler are provided with filler portions Bil which are adapted to extend in the spaces of the end bars of the grate to prevent fuel from falling through said spaces.

The construction described examplifies grate bars in which the lower portions are provided with wings and spaces for receiving corresponding wings of contiguous bars for producing greater shakin action at the lower portion of the inclined grate; upper portions with sides equidistant (from the longitudinal axis which do not interfit with contiguous bars for producing relatively less shaking action of the lower and intermediate portions of the bars. In this construction, the general contour of the projections 5: i s:members varying. p ogressively o p 4 on the opposite sides of the bars have parallel edges to form wings for producing greater shaking action and spaces for receivin similar wings on contiguous sections, and the wings on one grate bar will operate in corresponding contoured spaces in the contiguous bars.

In operation, the natural angle of the top of the fuel bed is slightly less in degree than the angle of the top of the grate so that the thickness of the firebed adjacent the lower portion of the grate is somewhat heavier than at the upper portion adjacent the magazine. As the fuel burns it slides down the grate toward the bottom and to maintain some fire near the bottom it is necessary to provide a heavier or thicker fire bed at this point. This also tends to cause the fuel to burn more evenly over the entire grate. When the grate is operated to discharge the accumulated ash into the ash pit, the wings 32, 45 and 55, which have the greatest width, will efiect a more violent agitation of the firebed at the lower portion of the grate and efiect relatively greater discharge of ash from the lower end. The rectangular member 68 of the bar will effect the least agitation of the firebed at the upper portion of the grate and the intermediate wings 55 will effect a gradually decreasing agitation between the lower portion of the grate and the upper portion. In this manner, grate bars extendin continuously from the upper and lower ends of the inclined grate will effect the proportionate or relatively different shaking action desired in all portions of the fuel bed, to take care of the different amounts of. ash produced over the grate bars. In consequence, it is not necessary to provide divided grate bars in the inclined grate to control the disposition of the ash by selectively different operation of the grate bar section. In this operation, the greater shaking action is achieved by operating transversely extending wings on one side of the bar through correspondingly contoured spaces in the contiguous bars.

The invention exemplifies an inclined grate in which the bars are formed to effect proportionate shaking action desired for maintainin desired distribution of the duel in the firebox and by which the difierent portions of the grate over which the fuel progressively passes downwardly will cause the removal of the ash in the proportions desired by a single shaking operation.

The invention is not to be understood as limited to the details described, since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a magazine type boiler having a fire-box, an inclined grate having its upper portion adjacent the magazine feed end of the firebox, comprising: co-operating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including acentral longitudinal member and wing-members projecting from the central member alternately on opposite sides of the bar provided with edges defining intermediate spaces for receiving the wing-members on an adjacent bar, the .edges on the wing-members on one bar coacting with the mating edges of wings on an adjacent bar, the size and spacing of the ashes in increased quantity toward the lower end of the grate.

2. In a magazin type boiler having a firebox, an inclined grate having its upper portion adjacentthe magazine feed end of the firebox, comprising: co-operating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes, each bar integrally including a central longitudinal member and integral outwardly convergent spaced wing-members projecting from the central member on opposite sides of the bar, provided with edges defining intermediate spaces substantially conforming to the edges of the wing-members on an adjacent bar, a wing-member on one side having a longitudinally inclined edge, the bar having an edge defining a space substantially corresponding to said longitudinally inclined edge, the edges of the members on one bar coacting with the mating edges of wings on an adjacent bar, the size and spacing of the Wing-members varying progressively to dump ashes in increased quantity toward the lower end of the rate.

3. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper member having substantially straight longitudinal sides, and a lower portion having a central longitudinal member, and spaced wing-members projecting from the central member alternately on opposite sides of the bar and provided with edges defining intermediate spaces substantially conforming to the edges of the wingmembers on an adjacent bar, the edges of the wing-members on one bar coacting with the mat- [ing edges of Wings on an adjacent bar, the size and spacing of the wing-members varying progressively to dump ashes in increased quan-- tity toward the lower end of the grate.

4. In a magazine typ boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper substantially rectangular member, and a lower portion having a central longitudinal member and spaced wing-members projecting from the central member on opposite sides of the bar, provided with edges forming convergent sides and defining intermediate spaces substantially conforming to the edges of the wing-members on an adjacent bar, the edges of the members on one bar coacting with the mating edges of Wings on an adjacent bar, the size and spacing of the wing-members varying progressively to dump ashes in increased quantity toward the lower end of the grate.

5. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper portion in substantially straight integral sides, and a lower portion having a central longitudinal member and spaced wingmembers including one having a longitudinally inclined side, below said upper member, said wing-members projecting from the central member alternately on opposite sides of the bar and provided with edges defining intermediate spaces an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper substantially rectangular portion, and a lower portion having a central longitudinal member, an integral wing-member having a longitudinally inclined side below said upper member and outwardly convergent wing-members, said wing-members projecting from the central member alternately on opposite sides of the bar and provided with edges defining spaces substantially conforming to the edges of th wingmembers on an adjacent bar, the edges of the members on one bar coacting with the mating edges of the wings on an adjacent bar, the size and spacing of the wing-members varying progressively to dump ashes in increased quantity toward the lower end of the grate.

7. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper portion provided with substantially continuous longitudinally extending sides and a lower portion having a central longitudinal member and spaced integral wingmembers projecting from the central member alternately on opposite sides of the bars, and provided with edges defining intermediate spaces substantially conforming to the edges of the members on an adjacent bar, the edges of the members on one bar coacting with the mating edges of wings on an adjacent bar, th size and spacing of the wings varying progressively to dump ashes in increased quantity toward the P lower end of th grate.

8. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: 00- operating individual grate bars, and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including an upper portion provided with substantially continuous longitudinally extending sides and having openings extending through its central portion, and a lower portion having a central longitudinal member and spaced integral wing-members projecting from the central member alternately on opposite sides of the bars and provided with edges defining intermediate spaces conforming to the edges of the wing-members on an adjacent bar, the edges of the members on one bar coacting with the mating edges of wings on an adjacent bar, the size and spacing of the wing-members varying progressively to dump ashes in increased quantity toward the lower end of the grate.

9. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including in its lower portion a central longitudinal member, a wingmember projecting from one side of the central member and having a longitudinally inclined edge and cross ribs and spaced wing-members projecting alternately on opposit sides of the bar and having convergent side edges defining spaces conforming substantially to the convergent wing-members, the edges of the wing-members coacting withmating edges on an adjacent bar, the wing-members being of progressively varying sizes and spaced relation to dump ashes from the firebox in progressively increasing quantity toward the lower end of the grate.

10. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the ieed end of the firebox, comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including in its lower portion a central longitudinal member, a wing-member projecting from one side of the central member, having a longitudinally inclined edge, a series of ribs on the opposite side of the central member terminating toleave a space conforming substantially to said longitudinally inclined edge, and spaced wingmembers projecting alternately on opposite sides of the bar and having convergent side edges defining spaces conforming substantially to the convergent wing-members, the edges of the wingmembers and the ends of the ribs coacting with mating edges on an adjacent bar, the wingmembers being of progressively varying sizes and spaced relationto dump ashes from the firebox in progressively increasing quantity toward the lower end of the grate.

11. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the ieed end of the firebox, comprising: co-operating individual grate bars; and means for pivotally supporting the upper, and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each .bar integrally including in its lower portion a central longitudinal member, a wing-member projecting from one side of the central member, having a longitudinally inclined edge, a series of ribs on the opposite side of the central member terminating toleave a space conforming substantially to the member having the longitudinally inclined edge, and spaced wing-membersprojecting alternately on opposite sides of the bar and having convergent side edges defining spaces conforming substantially to the convergent wing-members, some of the wings with convergent side edges having opening extending therethrough, the edges of the wing-members and the ends of the ribs coacting with mating dges on an adjacent bar, the wing-members being of progressively varying sizes and spaced relation to dump ashes from the firebox in progressively increasing quantity toward the lower end of the grate.

12. In a magazine type boiler having a firebox, an inclined grate having its upper portion adjacent the feed end of the firebox, comprising: c0- operating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including in its lower portion a central longitudinal member, a wing-member having a longitudinally inclined edge at one side of the central member, ribs with openings therebetween, extending between the central member and the longitudinally inclined edge; the bar on its opposite side bein provided with means leaving a space conforming substantially to the member having the longitudinally inclined edge, and spaced wingmembers having slots extending therethrough, projecting alternately on opposite sides of the bar and having convergent side edges defining spaces conforming substantially to the convergent wing-members, the edges of the wing-members coacting with mating edges on an adjacent bar, the Wing-members being of progressively varying sizes and spaced relation to dump ashes from the firebox in progressively increasing quantity toward the lower end of the grate.

13. In a magazine type boiler having a firebox, an inciined grate having its upper portion adjacent the feed end of the firebox; comprising: cooperating individual grate bars; and means for pivotally supporting the upper and lower ends of the bars for rocking movement on parallel inclined longitudinal axes; each bar integrally including in its lower portion a central longitudinal member; a wing-member having a substantially continuous longitudinally inclined side-edge at one side of the central member, a series of ribs projecting from the opposite side of the central member terminating to leave a space conforming substantially to the wing with the iongitudinally inclined edge, and spaced wing-members projecting alternately on opposite sides of the bar and having convergent side edges defining spaces conforming substantially to the convergent wing-members, the edges of the convergent wingmembers coacting with mating edges, and the wing with the longitudinally inclined edge coacting with the ends of the ribs, on an adjacent bar, the wing-members being of progressively varying sizes and spaced relation to dump ashes from the firebox in progressively increasing quantity toward the lower end of the grate.

WILLIAM S. ANDERSON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 838,906 Roller Dec. 18, l90 6 1,355,095 Kohout Oct. 5, 1920 1,400,722 Budd Dec. 20, 1921 1,459,980 McBurney June 26,1923 1,515,028 Gillett Nov. 11, 1924 FOREIGN PATENTS Number Country Date 355,730 France 1905 

